Aww, OP, I’ve been where you are 
When I chucked my crap exH out he barely bothered with his kids. Only had them when he had to when I was on call for me job. Didn’t so much as buy them a toothbrush in his flat with new gf. I literally did everything and had zero child free time.
When he bought his dream house with new gf I was absolutely gutted. I thought how come he gets to waltz off into the sunset into his new shiny life leaving me with all the crap and no time to meet anyone.
But then natural justice occurred. His relationship didn’t last long, he had to buy his way out of that house (losing a lot of mjney) and his new gf now doesn’t want to live with him and he’s just drifting about like the twat he is.
My teenage girls see him for who he is (an acquaintance who lives down the road, gets in touch every now and again) he contributes nothing to our life.
Our life is very rich in every way compared to his.
I know you don’t feel this right now. I know it hurts. But I guarantee you’ll come up smelling of roses.
Think of him and his sleep less nights and nappy changing. Haha…